The first instance of something that resembled modern sunglasses arose in the legal circles of 12th-century China, when conscientious judges used smoked quartz lenses to hide facial expressions while interrogating witnesses. In the 18th century, James Ayscough experimented with green and blue tinted lenses believing that the colour could correct vision impairments.
Sunglasses only crossed over to fashion accessory in 1929, when Foster Grant began to sell them at Woolworths as protection from the sun. And when ballooning enthusiast John MacCready found that his eyes had been damaged by overexposure to sunlight in an Atlantic crossing, he got in touch with Bausch & Lomb with the request for a protective but elegant pair of eyeglasses. The 1936 prototype that used Edwin Land’s Polaroid filter was immediately adopted by Army Air Corp pilots, later released to the public as ‘Ray-ban’ and, except for a brief period in the 1990s, Aviators haven’t gone out of fashion since.
Now, though style may seem like the only incentive to buy sunglasses, their protective properties should also be considered.
A UV filter is important. Our eyes always absorb some ultraviolet rays, but excessive exposure can cause long and short-term ocular problems—cataracts, photokeratits and even eye cancer. Sunglasses deceive our pupils into dilation, protecting them from harmful rays. A UV filter should block a minimum of 70% of the rays passing through it. A darker lens does not necessarily indicate better protection.
Polarized lenses (Polaroids) reduce glare, that isn’t just annoying but can be dangerous while driving. However LCDs (liquid crystal displays), which are sometimes part of car dashboard displays, appear invisible when viewed through polarized lenses from a certain angle.
If you spend a lot of time on a motorbike, then plastic, shatterproof glasses are important. For adventure sports, shatterproof may not be enough. Lightweight polycarbonate lenses that are extremely strong and impact-resistant are more reliable.
Prescription sunglasses are available from almost any optician. But if you will be wearing spectacles the entire day, getting photochromatic lenses are an option. Photochromatic lenses change colour depending on the amount of ultraviolet light they are exposed to. They are dark in sunlight but clear up indoors. They can be made of glass or plastic and are even available for transition lenses.
Colour of the lens does make a difference to vision. Grey makes things seem darker. Red causes much colour distortion and isn’t recommended for driving glasses. Yellow and orange lenses don’t affect colour perception much, but do enhance contrast, giving better depth perception and making them popular with golfers and shooters. Brown and green have properties that lie somewhere between yellow and grey. Lighter colours will always offer better visibility than darker colours.
It’s important to try on the sunglasses before buying them. Sunglasses, depending on the shape of their frame, change the way your face looks. Even variations on the same basic design can give illusions of roundness or length. Which is why buying off the internet or giving them as presents may not be a good idea.
However, if a frame is too loose around the head, it can usually be adjusted. Metal frames can be slightly bent and the screws at the hinges can be tightened. Plastic frames can be heated and readjusted for a better fit.
For the past few seasons, sunglasses styles have been based on retro models. Round and big is in—Aviators are still around, and Jackie-Os (named for what Jackie Kennedy Onassis used to wear) are back. With a little bit of design, extra colour on the side or a ‘bit of bling’, an old design can be transformed into something quite trendy.
Don’t buy sunglasses off the road. Even though they seem like an extremely good bargain, they definitely won’t be polarized or scratch proof, but more importantly, they will not offer UV protection. Basic sunglasses with UV protection begin at Rs 400. Polarized lenses cost at least Rs 1,000 more. Photochromatic lenses made of glass begin at Rs 600, while plastic ones cost Rs 1,500, regardless of the prescription. Designer sunglasses begin with Ray-bans that start at Rs 2,000, while most other brands (Christian Dior, Gucci, Oakley, and others) start at Rs 5,000.

Visit www.spectglasses.com for entire Range Of Designer Sunglasses.

Source: www.timesofindia.com

Be Sociable, Share!

• 

Bookmark to:

Hide Sites